When implementing a graph, what advantage does an adjacency matrix offer over an adjacency list?
Adjacency matrix provides O(1) edge lookup because: 1) Direct access to edge existence through matrix indices, 2) No need to search through lists of adjacent vertices, 3) Constant time edge weight updates for weighted graphs, 4) Better for dense graphs with many edges, 5) Simplifies implementation of some graph algorithms, 6) Efficient for graphs where edge existence is frequently queried, 7) Memory usage is O(V²) where V is number of vertices, 8) Trade-off between space and time complexity.